Expandable spinal implants

ABSTRACT

A spinal implant has proximal and distal regions, and includes upper and lower bodies. A proximal adjustment assembly is disposed between the upper and lower bodies in the proximal region of the spinal implant and is adjustably coupled to the upper and lower bodies, and a distal adjustment assembly is disposed between the upper and lower bodies in the distal region of the spinal implant and is adjustably coupled to the upper and lower bodies. The proximal and distal adjustment assemblies are independently movable with respect to each other, both concurrently and alternately, to change a vertical height of at least one of the proximal or distal regions of the spinal implant. A set screw is removably disposed within the proximal region of the spinal implant to lock the vertical height of the proximal and distal regions of the spinal implant.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.15/657,796, filed Jul. 24, 2017, the disclosure of which is incorporatedherein by reference.

TECHNICAL FIELD

The present disclosure relates generally to orthopedic surgical devices,and more particularly, to expandable spinal implants configured forpositioning within an intervertebral space, associated instrumentation,and methods of using the same.

BACKGROUND

The spinal column is a complex system of bones and connective tissuesthat provide support for the human body and protection for the spinalcord and nerves. The adult spine includes an upper portion and a lowerportion. The upper portion contains twenty-four discrete bones, whichare subdivided into three areas including seven cervical vertebrae,twelve thoracic vertebrae, and five lumbar vertebrae. The lower portionincludes the sacral and coccygeal bones. The cylindrical shaped bones,called vertebral bodies, progressively increase in size from the upperportion downwards to the lower portion.

An intervertebral disc along with two posterior facet joints cushion anddampen the various translational and rotational forces exerted upon thespinal column. The intervertebral disc is a spacer located between twovertebral bodies. The facets provide stability to the posterior portionof adjacent vertebrae. The spinal cord is housed in the canal of thevertebral bodies. It is protected posteriorly by the lamina. The laminais a curved surface with three main protrusions. Two transverseprocesses extend laterally from the lamina, while the spinous processextends caudally and posteriorly. The vertebral bodies and lamina areconnected by a bone bridge called the pedicle.

The spine is a flexible structure capable of a large range of motion.There are various disorders, diseases, and types of injury, whichrestrict the range of motion of the spine or interfere with importantelements of the nervous system. The problems include, but are notlimited to, scoliosis, kyphosis, excessive lordosis, spondylolisthesis,slipped or ruptured disc, degenerative disc disease, vertebral bodyfracture, and tumors. Persons suffering from any of the above conditionstypically experience extreme and/or debilitating pain, and often timesdiminished nerve function. These conditions and their treatments can befurther complicated if the patient is suffering from osteoporosis, orbone tissue thinning and loss of bone density.

Spinal discs between the endplates of adjacent vertebrae in a spinalcolumn of the human body provide critical support. However, due toinjury, degradation, disease, or the like, these discs can rupture,degenerate, and/or protrude to such a degree that the intervertebralspace between adjacent vertebrae collapses as the disc loses at least apart of its support function. This can cause impingement of the nerveroots and severe pain.

In some cases, surgical correction may be required. Some surgicalcorrections include the removal of the natural spinal disc from betweenthe adjacent vertebrae. In order to preserve the intervertebral discspace for proper spinal column function, an interbody spacer can beinserted between the adjacent vertebrae.

Typically, a prosthetic implant is inserted between the adjacentvertebrae and may include pathways that permit bone growth between theadjacent vertebrae until they are fused together. However, there existsa possibility that conventional prosthetic implants may be dislodged ormoved from their desired implantation location due to movement by thepatient before sufficient bone growth or fusion has occurred. Due to theconcave nature of the vertebral body endplates, it can be challenging toobtain enough contact between the implant and the endplates to createbone growth. Additionally, achieving the desired lordosis can bedifficult given the limitation of typical prosthetic implants once theyare implanted.

Therefore, a need exists for a spinal implant that provides maximumcontact with the vertebral body endplates, matches the desired amount oflordosis, allows for bone growth between adjacent vertebrae, maintainsthe space between adjacent vertebrae during bone ingrowth, and/orresists dislocation from its implantation site.

SUMMARY

In accordance with an aspect of the present disclosure, a spinal implanthaving a proximal region and a distal region includes an upper body, alower body, a proximal adjustment assembly, a distal adjustmentassembly, and a set screw. Each of the upper and lower bodies includesan outer surface and an inner surface, and the inner surfaces of theupper and lower bodies are disposed in opposed relation relative to eachother. The proximal adjustment assembly is disposed between the upperand lower bodies in the proximal region of the spinal implant and isadjustably coupled to the upper and lower bodies. The distal adjustmentassembly is disposed between the upper and lower bodies in the distalregion of the spinal implant and is adjustably coupled to the upper andlower bodies. The proximal and distal adjustment assemblies areindependently movable, both concurrently and alternately, to change avertical height of at least one of the proximal region or the distalregion of the spinal implant. The set screw is removably disposed withinthe proximal region of the spinal implant to lock the vertical height ofthe proximal and distal regions of the spinal implant.

In embodiments, the distal adjustment assembly includes a pivot linkageassembly including an upper pivot linkage pivotably connected to theinner surface of the upper body, a lower pivot linkage pivotablyconnected to the inner surface of the lower body, and a connectorlinkage pivotably connected to the upper and lower pivot linkages.Longitudinal movement of the connector linkage causes a correspondingmovement of the upper and lower pivot linkages with respect to eachother to change the vertical height of the distal region of the spinalimplant. In some embodiments, the distal adjustment assembly includes athreaded post including an elongated threaded body extending through theproximal adjustment assembly and a distal end disposed within a recessdefined in the connector linkage such that longitudinal translation ofthe threaded post effects movement of the pivot linkage assembly.

The distal adjustment assembly may include an expander including a bodyportion defining a cavity therein and a distal end including a doubleramped inner surface. The pivot linkage assembly may extend through thecavity of the expander such that the upper and lower pivot linkagescontact the double ramped inner surface of the expander when moved bythe threaded post. The expander may include a shaft extending proximallyfrom the body portion. The shaft may include a threaded opening definedtherein and the elongated threaded body of the threaded post may bethreadably engaged with the threaded opening of the shaft and axiallymovable therethrough into the cavity of the expander.

In embodiments, each of the inner surfaces of the upper and lower bodiesincludes a pair of proximal fins defining angled slots therethrough, andthe proximal adjustment assembly includes a linkage body includingdistal holes defined through lateral sides thereof and a first set ofpins disposed within the distal holes of the linkage body and into theangled slots of the upper and lower bodies. Movement of the linkage bodycauses the first set of pins to translate within the angled slots tochange the vertical height of the proximal region of the spinal implant.

In some embodiments, the proximal adjustment assembly includes a flangenut having a threaded opening defined therethrough that is threadablyengaged with the threaded post of the distal adjustment assembly, andthe linkage body includes a recess disposed between proximal and distalportions thereof in which the flange nut is disposed. Axial movement ofthe flange nut along the threaded post effects movement of the linkagebody. In certain embodiments, the proximal portion of the linkage bodyincludes a threaded inner surface and the set screw includes a threadedouter surface threadably engageable with the threaded inner surface ofthe linkage body to prevent the threaded post and the flange nut frommoving proximally with respect to the linkage body.

The pair of proximal fins of the upper and lower bodies may definevertical slots therethrough, and the proximal adjustment assembly mayinclude a coupler that includes a pair of nubs extending from lateralsides thereof that is slidably disposed within the vertical slots of theupper and lower bodies.

At least one of the outer surfaces of the upper body or the lower bodymay include a plurality of tapered ridges.

In accordance with another aspect of the present disclosure, a systemincludes a spinal implant and an insertion instrument. The spinalimplant has a proximal region and a distal region, and includes an upperbody, a lower body, a proximal adjustment assembly, and a distaladjustment assembly. Each of the upper and lower bodies includes anouter surface and an inner surface, and the inner surfaces of the upperand lower bodies are disposed in opposed relation relative to eachother. The proximal adjustment assembly is disposed between the upperand lower bodies in the proximal region of the spinal implant and isadjustably coupled to the upper and lower bodies. The distal adjustmentassembly is disposed between the upper and lower bodies in the distalregion of the spinal implant and is adjustably coupled to the upper andlower bodies. The proximal and distal adjustment assemblies areindependently movable, both concurrently and alternately, to change avertical height of at least one of the proximal region or the distalregion of the spinal implant. The insertion instrument includes a bodyportion having an elongated shaft extending along a longitudinal axis,and a connector assembly including connector arms pivotably secured toopposed sides of the elongated shaft. The connector arms are configuredto engage an outer surface of the spinal implant.

The proximal adjustment assembly of the spinal implant may include alinkage body pivotably coupled to the upper and lower bodies. Thelinkage body may have proximal cavities defined in lateral sidesthereof, and each connector arm of the insertion instrument may includean engagement feature radially movable relative to the longitudinal axissuch that the engagement features are movable in and out of engagementwith the proximal cavities of the spinal implant.

In embodiments, each engagement feature is disposed on a distal portionof the respective connector arm and the connector assembly includesconnector plates slidably disposed over the connector arms. When theconnector plates are disposed in a proximal position, the distalportions of the connector arms extend radially outwardly relative to thelongitudinal axis and when the connector plates are disposed in a distalposition, the distal portions of the connector arms are substantiallyaligned with the longitudinal axis.

In some embodiments, the body portion of the insertion instrumentincludes elongated rails slidably disposed on the opposed sides of theelongated shaft. The elongated rails are coupled to the connector platesof the connector assembly such that longitudinal movement of theelongated rails causes a corresponding longitudinal movement of theconnector plates between the proximal and distal positions. In certainembodiments, the body portion of the insertion instrument includes arotation knob threadably engaged with a proximal portion of theelongated shaft and coupled to proximal ends of the elongated rails suchthat rotation of the rotation knob causes longitudinal movement of theelongated rails.

The system may further include a driving instrument and/or a set screwdriver positionable through a lumen defined through the insertioninstrument. The driving instrument may be configured to actuate theproximal and distal adjustment assemblies. The set screw driver may beconfigured to engage a set screw with the spinal implant to lock aposition of the spinal implant.

In accordance with yet another aspect of the present disclosure, asystem includes a spinal implant and a driving instrument. The spinalimplant has a proximal region and a distal region, and includes an upperbody, a lower body, a proximal adjustment assembly, and a distaladjustment assembly. Each of the upper and lower bodies includes anouter surface and an inner surface, and the inner surfaces of the upperand lower bodies are disposed in opposed relation relative to eachother. The proximal adjustment assembly is disposed between the upperand lower bodies in the proximal region of the spinal implant and isadjustably coupled to the upper and lower bodies. The distal adjustmentassembly is disposed between the upper and lower bodies in the distalregion of the spinal implant and is adjustably coupled to the upper andlower bodies. The proximal and distal adjustment assemblies areindependently movable, both concurrently and alternately, to change avertical height of at least one of the proximal region or the distalregion of the spinal implant. The driving instrument includes an outershaft including a distal end configured to actuate the proximaladjustment assembly, a distal inner shaft disposed within the outershaft and including a distal end configured to actuate the distaladjustment assembly, and a proximal shaft assembly. The proximal shaftassembly includes a proximal outer shaft, a proximal inner shaftdisposed within the proximal outer shaft, and an adjustment knob foradjusting the position of the proximal inner shaft relative to theproximal outer shaft. A distal portion of the proximal outer shaft isdisposed within a proximal portion of the distal inner shaft, and theadjustment knob is movable between a height position configured to allowfor simultaneous actuation of the proximal and distal adjustmentassemblies, a proximal position configured to allow for actuation ofonly the proximal adjustment assembly and a distal position configuredto allow for actuation of only the distal adjustment assembly.

The proximal adjustment assembly of the spinal implant may include aflange nut that is longitudinally movable to drive a change in thevertical height of the proximal region of the spinal implant, and thedistal adjustment assembly of the spinal implant may include a threadedpost that is longitudinally movable to drive a change in the verticalheight of the distal region of the spinal implant. The flange nut mayinclude a threaded opening defined therethrough that is threadablyengaged with the threaded post.

In embodiments, the outer shaft of the driving instrument includes anopen distal tip having an inner surface configured to engage an outersurface of the flange nut, and the distal inner shaft of the drivinginstrument including a distal tip configured to engage a recessedproximal end of the threaded post.

In accordance with another aspect of the present disclosure, a method ofimplanting a spinal implant into a disc space between adjacent vertebralbodies includes: inserting a spinal implant that is releasably attachedto a distal end of an insertion instrument into a disc space; insertinga driving instrument into a lumen defined through the insertioninstrument and into engagement with the spinal implant; and adjusting atleast one of the proximal or distal adjustment assemblies of the spinalimplant with the driving instrument. The spinal implant includes anupper body, a lower body, a proximal adjustment assembly, and a distaladjustment assembly. Each of the upper and lower bodies includes anouter surface and an inner surface, and the inner surfaces of the upperand lower bodies are disposed in opposed relation relative to eachother. The proximal adjustment assembly is disposed between the upperand lower bodies in the proximal region of the spinal implant and isadjustably coupled to the upper and lower bodies. The distal adjustmentassembly is disposed between the upper and lower bodies in the distalregion of the spinal implant and is adjustably coupled to the upper andlower bodies. The proximal and distal adjustment assemblies areindependently movable, both concurrently and alternately, to change avertical height of at least one of the proximal region or the distalregion of the spinal implant. The driving instrument includes an outershaft including a distal end configured to actuate the proximaladjustment assembly, a distal inner shaft disposed within the outershaft and including a distal end configured to actuate the distaladjustment assembly, and a proximal shaft assembly. The proximal shaftassembly includes a proximal outer shaft, a proximal inner shaftdisposed within the proximal outer shaft, and an adjustment knob foradjusting the position of the proximal inner shaft relative to theproximal outer shaft. A distal portion of the proximal outer shaft isdisposed within a proximal portion of the distal inner shaft, and theadjustment knob is movable between a height position configured to allowfor simultaneous actuation of the proximal and distal adjustmentassemblies, a proximal position configured to allow for actuation ofonly the proximal adjustment assembly and a distal position configuredto allow for actuation of only the distal adjustment assembly.

The method may further include attaching the spinal implant to thedistal end of the insertion instrument with the outer surfaces of theupper and lower bodies substantially parallel to each other. The methodmay further include locking the position of the spinal implant with aset screw. The may further include adjusting the vertical height of atleast one of the proximal or distal regions of the spinal implant priorto inserting the spinal implant into the disc space.

In embodiments, adjusting at least one of the proximal or distaladjustment assemblies includes setting the driving instrument to theheight position to actuate both the proximal and distal adjustmentassemblies such that the upper and lower bodies of the spinal implantare expanded while maintaining the upper and lower bodies insubstantially parallel relation to each other until the spinal implantengages the vertebral bodies. In some embodiments, the method furtherincludes individually actuating at least one of the proximal or distaladjustment assemblies to adjust the height of at least one of theproximal or distal regions of the spinal implant to accommodatelordosis. In certain embodiments, adjusting at least one of the proximalor distal adjustment assemblies includes setting the driving instrumentto the proximal or distal position to individually actuate the proximalor distal adjustment assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the disclosureand, together with a general description of the disclosure given above,and the detailed description of the embodiments given below, serve toexplain the principles of the disclosure, wherein:

FIG. 1 is a perspective view, with parts separated, of a spinal implantand a set screw in accordance with an embodiment of the presentdisclosure;

FIG. 2 is an exploded view of the spinal implant of FIG. 1;

FIG. 3A is a perspective view of the spinal implant of FIG. 1, with theset screw removed;

FIG. 3B is a perspective view of the spinal implant of FIG. 3A, withpivot pins separated;

FIG. 4A is a perspective view of the spinal implant of FIG. 1, withadjustment assemblies removed;

FIG. 4B is an exploded perspective view of the spinal implant of FIG.4A, with parts separated;

FIG. 5A is a perspective view of the spinal implant of FIG. 1, withparts removed;

FIG. 5B is a perspective view of the spinal implant of FIG. 5A, withparts separated;

FIG. 6A is a top view of the spinal implant of FIG. 1, in a collapsedposition;

FIG. 6B is a cross-sectional view of the spinal implant of FIG. 6A,taken along line 6B-6B of FIG. 6A;

FIG. 7A is a side view of the spinal implant of FIGS. 6A and 6B;

FIG. 7B is a top cross-sectional view of the spinal implant of FIGS.6A-7A, taken along line 7B-7B of FIG. 7A;

FIGS. 8A and 8B are end views of the spinal implant of FIGS. 6A-7B;

FIG. 9A is an end view of the spinal implant of FIG. 1, with a distalregion of the spinal implant fully expanded;

FIG. 9B is a side cross-sectional view of the spinal implant of FIG. 9A,taken along line 9B-9B of FIG. 9A;

FIG. 10 is a side view of the spinal implant of FIGS. 9A and 9B;

FIG. 11A is an end view of the spinal implant of FIG. 1, with a proximalregion of the spinal implant fully expanded;

FIG. 11B is a side cross-sectional view of the spinal implant of FIG.11A, taken along line 11B-11B of FIG. 11A;

FIG. 12 is a side view of the spinal implant of FIGS. 11A and 11B;

FIG. 13A is an end view of the spinal implant of FIG. 1, with proximaland distal regions of the spinal implant fully expanded;

FIG. 13B is a side cross-sectional view of the spinal implant of FIG.13A, taken along line 13B-13B of FIG. 13A;

FIG. 14 is a side view of the spinal implant of FIGS. 13A and 13B;

FIG. 15 is a side view of the spinal implant of FIGS. 13A-14 includingthe set screw of FIG. 1;

FIG. 16A is an end view of the spinal implant and the set screw of FIG.15;

FIG. 16B is a side cross-sectional view of the spinal implant and theset screw of FIGS. 15 and 16A, taken along line 16B-16B of FIG. 16A;

FIG. 17 is a perspective view of a system including the spinal implantof FIG. 1 and an insertion instrument, in accordance with an embodimentof the present disclosure;

FIG. 18A is a side view of the system of FIG. 17;

FIG. 18B is a top cross-sectional view of the system of FIGS. 17 and18A, taken along line 18B-18B of FIG. 18A;

FIG. 19A is a perspective view of the system of FIG. 17, with theinsertion instrument in an open position and the spinal implant alignedwith the insertion instrument;

FIG. 19B is a close-up view of the area of detail indicated in FIG. 19A;

FIG. 20A is a perspective view of the system of FIG. 17, with theinsertion instrument in a closed position and the spinal implantreleasably secured to the insertion instrument;

FIG. 20B is a close-up view of the area of detail indicated in FIG. 20A;

FIG. 21 is a perspective view of a system including the spinal implantof FIG. 1 and a driving instrument, in accordance with an embodiment ofthe present disclosure;

FIG. 22 is a perspective view of a system including the spinal implantof FIG. 1, the insertion instrument of FIG. 17, and the drivinginstrument of FIG. 21, in accordance with an embodiment of the presentdisclosure;

FIG. 23 is a perspective view of the driving instrument of FIGS. 21 and22, with parts separated;

FIG. 24A is a side view of the driving instrument of FIGS. 21 and 22, ina height position;

FIG. 24B is a cross-sectional view of the driving instrument of FIG.24A, taken along line 24B-24B of FIG. 24A;

FIG. 25A is a side view of the driving instrument of FIGS. 21 and 22, ina posterior position;

FIG. 25B is a cross-sectional view of the driving instrument of FIG.25A, taken along line 25B-25B of FIG. 25A;

FIG. 26A is a side view of the driving instrument of FIGS. 21 and 22, inan anterior position;

FIG. 26B is a cross-sectional view of the driving instrument of FIG.26A, taken along line 26B-26B of FIG. 26A;

FIG. 27 is a perspective view of the system of FIG. 22;

FIG. 28A is a side view of the system of FIG. 27, with the drivinginstrument in an anterior position;

FIG. 28B is a cross-sectional view of the system of FIG. 28A, takenalong line 28B-28B of FIG. 28A;

FIG. 28C is a close-up view of the area of detail indicated in FIG. 28B;

FIG. 29A is a side view of the system of FIG. 27, with the drivinginstrument in a posterior position;

FIG. 29B is a cross-sectional view of the system of FIG. 29A, takenalong line 29B-29B of FIG. 29A;

FIG. 29C is a close-up view of the area of detail indicated in FIG. 29B;

FIG. 30 is a perspective view of a system including the spinal implantof FIG. 1, the insertion instrument of FIG. 17, and a set screw driverin accordance with another embodiment of the present disclosure;

FIG. 31 is a top view of a disc spreader in accordance with anembodiment of the present disclosure;

FIG. 32 is a side view of the disc spreader of FIG. 31; and

FIG. 33 is a perspective view of the disc spreader of FIGS. 31 and 32.

DETAILED DESCRIPTION

Embodiments of the present disclosure are now described in detail withreference to the drawings in which like reference numerals designateidentical or corresponding elements in each of the several views. Theterm “clinician” refers to a doctor (e.g., a surgeon), a nurse, or anyother care provider, and may include support personnel. Throughout thisdescription, the term “proximal” refers to a portion of a system,device, or component thereof that is closer to a clinician, and the term“distal” refers to the portion of the system, device, or componentthereof that is farther from the clinician.

Referring now to the drawings, FIG. 1 illustrates an expandable spinalimplant or a spinal implant 100 in accordance with an embodiment of thepresent disclosure. Spinal implant 100 has a proximal region 100 a and adistal region 100 b extending along a longitudinal axis “X.” The spinalimplant 100 includes an upper body 110 and a lower body 130 disposed inopposed relation relative to each other and coupled together by aproximal adjustment assembly 150 and a distal adjustment assembly 170.The proximal and distal adjustment assemblies 150, 170 are independentlymovable to allow for adjustment in the angular relationship and verticaldistance between the upper and lower bodies 110, 130 of the proximal anddistal regions 100 a, 100 b of the spinal implant 100. Accordingly, thespinal implant 100 is movable between a collapsed configuration and afully expanded configuration, and includes a number of partiallyexpanded configurations, as described in further detail below. Thedesired configuration of the spinal implant 100 may be locked in placevia a set screw 10 that is engageable with the proximal and distaladjustment assemblies 150, 170, as also described in further detailbelow.

Turning now to FIG. 2, the upper body 110 of the spinal implant 100includes an elongated substantially planar portion 112 having a proximalportion 112 a, a distal portion 112 b, and a curved portion 114 disposeddistally of the planar portion 112. An outer surface 116 of the planarportion 112 includes a plurality of retaining features 116 a in the formof tapered ridges. In embodiments, the tapered ridges may be formed by3D printing to produce customized structures. The plurality of retainingfeatures 116 a are configured to frictionally engage an adjacent surfaceof a vertebral body (e.g., a vertebral endplate) to maintain theposition of the spinal implant 100 relative to the vertebral body and/orto inhibit the spinal implant 100 from backing out of the intervertebralspace as the plurality of retaining features 116 a may bite into thevertebral endplate. It should be understood that the plurality ofretaining features 116 a may have other ridge configurations, or may beprotrusions, bumps, teeth, or other texturized structures within thepurview of those skilled in the art. It should further be understoodthat the plurality of retaining features 116 a may be formed by otherprocesses (e.g., etching or molding techniques) within the purview ofthose skilled in the art.

An inner surface 118 of the upper body 110 includes a pair of proximalfins 120 extending from the proximal portion 112 a of the planar portion112 and a pair of distal posts 122 extending from the distal portion 112b of the planar portion 112 proximate to the curved portion 114. Eachproximal fin 120 includes an angled slot 120 a and a vertical slot 120 bdefined therein that are opposed and aligned with the respective angledand vertical slots 120 a, 120 b of the other proximal fin 120. Theangled slot 120 a is disposed proximal to the vertical slot 120 b. Eachdistal post 122 includes a through hole 122 a defined therethrough thatare opposed and aligned with each other. It should be understood thatthe proximal fin 120 and the distal post 122 that are not fully shownare identical to the proximal fin 120 and the distal post 122 shown, andsimilar to the proximal fins 140 and the distal posts 142 of the lowerbody 130, as described in further detail below.

The lower body 130 includes an elongated substantially planar portion132 having a proximal portion 132 a and a distal portion 132 b, and acurved portion 134 disposed distally of the planar portion 132. Theplanar portion 132 includes an outer surface 136 having a plurality ofretaining features 136 a (FIG. 6B) disposed thereon that are configuredto frictionally engage an adjacent surface of a vertebral body asdiscussed above with regard to the plurality of retaining features 116 aof the upper body 110. An inner surface 138 of the lower body 130includes a pair of proximal fins 140 extending from the proximal portion132 a of the planar portion 132, and a pair of distal posts 142extending from the distal portion 132 b of the planar portion 132proximal of the curved portion 134. Each proximal fin 140 includes anangled slot 140 a and a vertical slot 140 b defined therein that areopposed and aligned with the respective angled and vertical slots 140 a,140 b of the other proximal fin 140. Each distal post 142 includes athrough hole 142 a defined therethrough that are opposed and alignedwith each other.

The proximal adjustment assembly 150 includes a linkage body 152, aproximal rotational actuator (e.g., a flange nut 154) positionablewithin the linkage body 152, and a coupler 156 disposed distally of thelinkage body 152. The linkage body 152 includes a proximal portion 152 aand a distal portion 152 b, and defines a central opening 151therethrough, The proximal portion 152 a of the linkage body 152includes a threaded inner surface 153 configured to mate with a threadedouter surface 12 (FIG. 1) of the set screw 10. The distal portion 152 bof the linkage body 152 b includes a recess 155 defined between a pairof arms 158 extending along lateral sides of the linkage body 152. Thearms 158 include proximal cavities 158 a that are dimensioned to engagean insertion instrument 200 (see e.g. FIG. 17) and distal holes 158 bthat are aligned with the angled slots 120 a, 140 a of the proximal fins120, 140 of the upper and lower bodies 110, 130.

As shown in FIGS. 3A and 3B, in conjunction with FIG. 2, a first set ofpins 157 respectively extends through and frictionally engages thedistal holes 158 b of the linkage body 152 and the angled slots 120 a,140 a of the proximal fins 120, 140 of the upper and lower bodies 110,130 to adjustably couple the upper and lower bodies 110, 130 togethervia the linkage body 152. The first set of pins 157 is configured toride along the angled slots 120 a, 140 a of the proximal fins 120, 140of the upper and lower bodies 110, 130 as the linkage body 152 is movedproximally and/or distally between the upper and lower bodies 110, 130.

With continued reference to FIG. 2, the coupler 156 includes a centralopening 159 defined therein that is aligned with the central opening 151of the linkage body 152. The central openings 151, 159 of the linkagebody 152 and the coupler 156 are sized and shaped to engage, and besupported on, a shaft 184 of an expander 174 of the distal adjustmentassembly 170. As shown in FIGS. 4A and 4B, in conjunction with FIG. 2,nubs 160 have flanged inner ends 160 a that are dimensioned to beretained within the coupler 156 such that elongate bodies 160 b of thenubs 160 extend laterally through side openings 161 of the coupler 156and slide within the vertical slots 120 b, 140 b of the proximal fins120, 140 of the upper and lower bodies 110, 130.

As shown in FIGS. 5A and 5B, in conjunction with FIG. 2, the flange nut154 includes a proximal portion 154 a and a flanged distal portion 154b. The proximal portion 154 a includes a threaded opening 163 definedtherethrough that is configured to threadably engage a threaded post 172of the distal adjustment assembly 170, and a shaped outer surface 165that is configured to mate with a driving instrument 300 (see e.g., FIG.21) such that either the flange nut 154 or the threaded post 172 may berotated and axially translated with respect to the other. The flangeddistal portion 154 b is dimensioned to be received within the recess 155of the linkage body 152. Accordingly, movement of the flange nut 154distally moves the linkage body 152 distally causing the first set ofpins 157 to translate within the angled slots 120 a, 140 a of theproximal fins 120, 140 and the nubs 160 of the coupler 156 to translatewithin the vertical slots 120 b, 140 b of the proximal fins 120, 140 toincrease the distance between the upper and lower bodies 110 and 130 inthe proximal region 100 a of the spinal implant 100. Conversely,movement of the flange nut 154 proximally moves the linkage body 152proximally to reduce the distance between the upper and lower bodies110, 130 in the proximal region 100 a of the spinal implant 100.

Referring again to FIG. 2, the distal adjustment assembly 170 includes adistal rotational actuator (e.g., the threaded post 172), an expander174, and a pivot linkage assembly 175 including an upper pivot linkage176, a lower pivot linkage 178, and a connector linkage 180. Thethreaded post 172 includes an elongated threaded body 172 a having arecessed proximal end 172 b configured to mate with a driving instrument300 (see e.g., FIG. 21) and a distal end 172 c. The recessed proximalend 172 b may have a hex feature, e.g., hexagonal or hexolobular inshape, or any other suitable configuration that is engageable with asuitable driving instrument to enable the driving instrument to controlthe insertion and/or advancement, as well as retraction and/orwithdrawal, of the threaded post 172 within the spinal implant 100.

The expander 174 includes a body portion 182 defining a cavity 182 atherein. A pair of opposed longitudinal slots 181 is disposed on lateralsides of the body portion 182, and a distal end of the body portion 182includes a double ramped inner surface 182 b (see e.g., FIG. 9B). Ashaft 184 extends proximally from the body portion 182 of the expander174 and defines a threaded opening 184 a therein that is configured tothreadably engage the elongated threaded body 172 a of the threaded post172.

The pivot linkage assembly 175 includes an upper pivot linkage 176having an upper body 176 a defining an upper hole 177 therethrough andlower legs 176 b extending from the upper body 176 a, each of the lowerlegs 176 b including a lower hole 179 defined therethrough. The pivotlinkage assembly 175 further includes a lower pivot linkage 178 havingan upper hole 178 a and a lower hole 178 b defined therethrough, and aconnector linkage 180 including a proximal body 180 a defining a recess183 therein and distal legs 180 b extending from the proximal body 180a, each of the distal legs 180 b defining a distal hole 185therethrough.

As shown in FIGS. 2 and 4B, the upper hole 177 of the upper pivotlinkage 176 is aligned with the through holes 122 a defined in thedistal posts 122 of the upper body 110, and a second set of pins 186 isinserted therethrough for pivotably connecting the upper pivot linkage176 with the upper body 110. It is contemplated that a single pin couldbe used to pivotably connect the upper pivot linkage 176 with the upperbody 110. With continued reference to FIG. 2, the lower hole 178 b ofthe lower pivot linkage 178 is aligned with the through holes 142 adefined in the distal posts 142 of the lower body 130, and a pin 187 isinserted therethrough for pivotably connecting the lower pivot linkage178 with the lower body 130. The lower holes 179 of the upper pivotlinkage 176, the upper hole 178 a of the lower pivot linkage 178, andthe distal holes 185 of the connector linkage 180 are aligned with eachother and with the longitudinal slots 181 defined in the expander 174such that the upper pivot linkage 176, the lower pivot linkage 178, andthe connector linkage 180 are disposed within the cavity 182 a in thebody portion 182 of the expander 174, and a pin 188 is disposedtherethrough for pivotably securing the upper and lower bodies 110 and130 to the expander 174 of the distal adjustment assembly 170 via thepivot linkage assembly 175. The recess 183 of the connector linkage 180is configured to receive the distal end 172 c of the threaded post 172therein to prevent the threaded post 172 from being removed from thespinal implant 100 during proximal movement thereof. This arrangementallows for simultaneous translation of the pin 188 within thelongitudinal slots 181 of the expander 174 and pivoting movement of theupper and lower pivot linkages 176, 178 during longitudinal translationof the threaded post 172.

In use, the threaded post 172 is rotated in a first direction to advancethe threaded post 172 distally which pushes the connector linkage 180distally and drives the upper and lower pivot linkages 176, 178 againstthe double ramped inner surface 182 b of the expander 174 therebyincreasing the height between the upper and lower bodies 110, 130 at thedistal region 100 b of the spinal implant 100. Rotation of the threadedpost 172 in a second, reverse direction moves the threaded post 172proximally which, in turn, moves the connector linkage 180 proximally toallow the upper and lower pivot linkages 176, 178 to collapse, therebydecreasing the height between the upper and lower bodies 110, 130 at thedistal region 100 b of the spinal implant 100.

Accordingly, the upper and lower pivot linkages 176, 178 are coupled tothe upper and lower bodies 110, 130, and are pivotable relative to eachother about the pin 188 to change the distance between the upper andlower bodies 110, 130, and thus, the angular position and verticalheight of the spinal implant 100 about the distal region 100 b of thespinal implant 100. Thus, the proximal and distal regions 100 a and 100b of the spinal implant 100 are independently movable with respect toeach other via the proximal and distal adjustment assemblies 150, 170 sothat the spinal implant 100 may have a variety of configurations.

The independent adjustability of the proximal and distal regions 100 a,100 b of the spinal implant 100 allows a clinician to adjust thedimensions of the spinal implant 100 (i.e., vertical heights of theproximal and distal regions) such that the spinal implant 100 can beinserted between two vertebrae with relatively narrow access in anunexpanded position, without force, to avoid trauma to the vertebralbodies, and in particular, the endplates of the vertebral bodies. Theproximal and/or distal regions 100 a, 100 b of the spinal implant 100can then be adjusted to partially or fully expanded positions so thatthe upper and lower bodies 110, 130 are aligned with the endplates tomaximize surface contact between the spinal implant 100 and theendplates, and to match the dimensions of the disc space defined betweenthe endplates in which the spinal implant 100 is disposed. Theadjustability of the spinal implant 100 allows a clinician, for example,to minimize trauma to the vertebrae during implantation of the spinalimplant 100, to tailor the spinal implant 100 to conform to the anatomyof individual patients, to maximize contact between the spinal implant100 and the endplates to create bone growth, to match the natural discheight of the disc space, to obtain a desired amount of lordosis for thespine, to improve the seating of the spinal implant 100 within the discspace, and/or to lessen the likelihood of expulsion of the spinalimplant 100 from the disc space.

Referring now to FIGS. 6A-8B, the spinal implant 100 has a collapsed, orunexpanded, position. In the collapsed position, the planar portions112, 132 of the upper and lower bodies 110, 130 are disposed in parallelrelationship to each other. As specifically shown in FIG. 6B, each ofthe proximal and distal regions 100 a, 100 b of the spinal implant 100has a height, “h1”, that defines the minimum distance at which the upperand lower bodies 110, 130 may be positioned relative to each other. Inembodiments, the height “h1” may range from about 3 mm to about 18 mm,and in some embodiments, the height “h1” is from about 8 mm to about 13mm. As shown in FIGS. 7A and 7B, the first set of pins 157 of thelinkage body 152 and the nubs 160 of the coupler 156 are disposed withinthe angled slots 120 a, 140 a and the vertical slots 120 b, 140 b,respectively, of the proximal fins 120, 140 of the upper and lowerbodies 110, 130 such that the first set of pins 157 and the nubs 160respectively rest within uppermost portions of the angled slots 120 a,140 a and the vertical slots 120 b, 140 b of the upper and lower bodies110, 130. The pin 188, which is disposed through the expander 174 andthe pivot linkage assembly 175, is disposed in a proximalmost positionwithin the longitudinal slots 181 of the expander 174.

As shown in FIGS. 9A-10, the threaded post 172 may be moved proximallyand distally to change the distance between the upper and lower bodies110, 130 in the distal region 100 b of the spinal implant 100. Rotationof the threaded post 172 in a first direction moves the threaded post172 distally through the threaded opening 163 of the flange nut 154 andthe threaded opening 184 a of the shaft 184 of the expander 174 which,in turn, moves the connector linkage 180 distally which, in turn, pushesthe upper and lower pivot linkages 176, 178 into the double ramped innersurface 182 b of the expander 174 to change the distance between theupper and lower bodies 110, 130 in the distal region 100 b of the spinalimplant 100. As specifically shown in FIG. 9B, the distal region 110 bof the spinal implant 100 has a height, “h2”, that defines the maximumdistance at which the upper and lower bodies, 110, 130 may be positionedrelative to each other in the distal region 110 b of the spinal implant100. In embodiments, the height “h2” may range from about 5 mm to about22 mm, and in some embodiments, the height “h2” is from about 10 mm toabout 15 mm. As specifically shown in FIG. 10, when the distal region100 b of the spinal implant 100 is fully expanded, the pin 188 isdisposed in a distalmost position within the longitudinal slot 181 ofthe expander 174. It should be understood that the threaded post 172 maybe rotated to achieve any of a number of partially expanded positions ofthe distal region 100 b of the spinal implant 100 between heights “h1”and “h2”.

As shown in FIGS. 11A-12, the flange nut 154 may be moved proximally anddistally to change the distance between the upper and lower bodies 110,130 in the proximal region 100 a of the spinal implant 100. Rotation ofthe flange nut 154 in a first direction moves the flange nut 154 and thelinkage body 152 distally such that the first set of pins 157 slidewithin the angled slots 120 a, 140 a of the proximal fins 120, 140 ofthe upper and lower bodies 110 and 130, and the nubs 160 of the coupler156 slide within the vertical slots 120 b, 140 b of the proximal fins120, 140 to expand the proximal region 100 a of the spinal implant 100.As specifically shown in FIG. 11B, the proximal region 100 a of thespinal implant 100 has a height “h3”, that defines the maximum distanceat which the upper and lower bodies 110, 130 may be positioned relativeto each other in the proximal region 110 a of the spinal implant 100. Inembodiments, the height “h3” may range from about 5 mm to about 22 mm,and in some embodiments, the height “h3” is from about 10 mm to about 15mm. As specifically shown in FIG. 12, the proximal region 100 a of thespinal implant 100 is fully expanded when the first set of pins 157 aredisposed within distalmost portions of the angled slots 120 a, 140 a ofthe upper and lower bodies 110, 130. It should be understood that theflange nut 154 may be rotated to achieve any number of partiallyexpanded positions of the proximal region 100 a of the spinal implant100 between heights “h1” and “h2”.

It is contemplated that the threads on the threaded post 172 may beprovided as variable pitch threads over all or a part of the length ofthe elongated threaded body 172 a of the threaded post 172 such that thenumber of turns required to expand the proximal and/or distal adjustmentassemblies 150, 170 is variable, having a fast expansion period alongpart of the threaded post 172 and a slow or fine expansion period alonganother part of the threaded post 172. Alternatively, the threads of thethreaded post 172 may be double lead threads to provide faster expansionper turn of the threaded post 172.

A person of ordinary skill in the art will readily understand that theproximal and distal regions of the spinal implant may be independentlyadjusted to achieve a desired configuration of the spinal implant.Accordingly, it is contemplated that only the proximal region or thedistal region of the spinal implant may be expanded, should that be adesired configuration, or both the proximal and distal regions of thespinal implant may be expanded (e.g., concurrently or alternately) toachieve a desired configuration (e.g., an implant having a kyphoticshape, a lordotic shape, etc.).

For example, in FIGS. 13A-14, the spinal implant 100 is shown with theproximal and distal regions 100 a of the spinal implant 100 each in afully expanded position. As shown in FIGS. 15-16B, once the desiredpositions of the proximal and distal regions 100 a, 100 b of the spinalimplant 100 are achieved, the set screw 10 may inserted into the linkagebody 152 to lock the position of the spinal implant 100. The set screw10 engages the threaded inner surface 153 at the proximal portion 152 aof the linkage body 152. When so positioned, the set screw 10 blocks thethreaded post 172 and the flange nut 154 from moving proximally relativeto the linkage body 152, thereby preventing the surgical implant 100from retracting and collapsing after surgery. Of course, if revision isnecessary, the set screw 10 may be removed to access the threaded post172 and/or the flange nut 154 to collapse the spinal implant 100 forremoval or to make further adjustment(s) to the spinal implant 100.

Referring now to FIGS. 17-18B, the spinal implant 100 and an insertioninstrument 200 are shown. The insertion instrument 200 includes, fromproximal to distal, a handle 210, a body portion 220, and a connectorassembly 230 extending along a longitudinal axis “Y” that is coincidentwith the longitudinal axis “X” (FIG. 1) of the spinal implant 100. Alumen 201 is defined through the insertion instrument 200 (i.e., thehandle 210, the body portion 220, and the connector assembly 230) andconfigured to receive a tool 300 (see e.g., FIG. 22) such as, forexample, driving instruments for rotating the threaded post 172 and/orthe flange nut 154 of the spinal implant 100.

The body portion 220 includes an elongated shaft 222, elongated rails224 slidably movable along tracks 226 disposed on opposed sides of theelongated shaft 222, and a rotation knob 228 disposed about a proximalportion 222 a of the elongated shaft 222. The rotation knob 228 includesa threaded inner surface 228 a that is threadably engaged with theproximal portion 222 a of the elongated shaft 222, and a distal recess228 b defined in the inner surface 228 a that is configured to receiveproximal flanges 224 a of the elongated rails 224.

Each of the elongated rails 224 includes a proximal flange 224 a and adistal flange 224 b. As discussed above, the proximal flanges 224 a ofthe elongated rails 224 are engaged with the distal recess 228 b of therotation knob 228. The distal flanges 224 b of the elongated rails 224are engaged with respective proximal openings 236 a defined in connectorplates 236 of the connector assembly 230.

The connector assembly 230 includes connector arms 232 pivotally securedto opposed sides of the elongated shaft 222 of the body portion 220 viapivot pins 234, and connector plates 236 slidably disposed over theconnector arms 232. Each of the connector arms 232 includes a proximalportion 232 a and a distal portion 232 b that are disposed at angleswith respect to the longitudinal axis “Y” of the insertion instrument200. The proximal portion 232 a of each connector arm 232 includes aprotrusion 238 on an outer surface thereof, and the distal portion 232 bof each connector arm 232 includes an engagement feature 240 (e.g., ahook) on an inner surface thereof.

The connector plates 236 each include a u-shaped body configured toengage and longitudinally ride the tracks 226 of the elongated shaft222. Each of the connector plates 236 includes a proximal opening 236 aengaged with the respective distal flange 224 b of the elongated rails224, and a distal opening 236 b configured to receive the respectiveprotrusion 238 of the connector arms 232 when the connector arms 232 aredisposed in a closed or grasping position.

As shown in FIGS. 19A and 19B, when the rotation knob 228 of theinsertion instrument 200 is disposed in a proximal position, theelongated rails 224 and the connector plates 236 are also disposed in aproximal position. In the proximal position, the cover plates 236 aredisposed over the proximal portions 232 a of the connector arms 232 suchthat the proximal portions 232 a are substantially aligned with thelongitudinal axis “Y” of the insertion instrument 200, and the distalportions 232 b of the connector arms 232 extend radially outwardlyrelative to the longitudinal axis “Y”. In the proximal position, theconnector arms 232 are in an open position such that the spinal implant100 may be placed adjacent the connector assembly 230 of the insertioninstrument 200, with the proximal cavities 158 a of the linkage body 152aligned with the engagement features 240 of the insertion instrument200.

As shown in FIGS. 20A and 20B, the rotation knob 228 of the insertioninstrument 200 may be moved to a distal position by rotating therotation knob 228 in a first direction which causes a correspondinglongitudinal movement of the elongated rails 224 and the connectorplates 236 along the tracks 226 of the elongated shaft 222. The distalmovement of the connector plates 236 over the connector arms 232 causesthe connector arms 232 to pivot about the pivot pin 234 (FIG. 18B) suchthat the distal portions 232 b of the connector arms 232 aresubstantially aligned/parallel with the longitudinal axis “Y” of theinsertion instrument 200 and the proximal portions 232 a of theconnector arms 232 extend radially outwardly such that the protrusions238 are deflected into the distal openings 236 b of the connector plates236. In the distal position, the connector arms 232 are in a closed orgrasping position and the engagement features 240 of the insertioninstrument 200 are engaged with the proximal cavities 158 a of thespinal implant 100 thereby releasably securing the insertion instrument200 to the spinal implant 100. As shown in FIGS. 19A-20B, the width ofthe body portion 220 of the insertion instrument 200, when attached tothe spinal implant 100, is no wider than the spinal implant 100. Thiscorresponding instrument body portion 220 width is important, as itfacilitates insertion and manipulation of the spinal implant 100 withthe insertion instrument 200 in the limited space available duringsurgery.

Additionally or alternatively, as shown in FIGS. 21 and 22, a drivinginstrument 300 may be used with the spinal implant 100, alone (FIG. 21)or in conjunction with the insertion instrument 200 (FIG. 22).

With reference now to FIG. 23, the driving instrument 300 includes anouter shaft 310, a distal inner shaft 320, and a proximal shaft assembly330. The outer shaft 310 defines a lumen 311 therethrough, and includesa proximal base portion 312 and an elongated body portion 314terminating at an open tip 316. The open tip 316 includes an innersurface 316 a (see e.g., FIG. 24B) that is complementary in shape withthe shaped outer surface 165 (see e.g., FIG. 2) of the flange nut 154 ofthe spinal implant 100 to engage the flange nut 154.

The distal inner shaft 320 includes a proximal base portion 322 and anelongated body portion 324 terminating at a distal tip 326. The proximalbase portion 322 is disposed within the proximal base portion 312 of theouter shaft 310, and the elongated body 324 is disposed within theelongated body portion 314 of the outer shaft 310. The distal innershaft 320 is biased in a proximal position via a biasing member 328(e.g., a coiled spring) disposed over the elongated body 324 and withinthe proximal base portion 312 of the outer shaft 310. A connector 329 isalso disposed within the proximal base portion 312 of the outer shaft310, proximal to the proximal base portion 322 of the distal inner shaft320. The distal tip 326 is a male connector having a complementarygeometry to the recessed proximal end 172 b (see e.g., FIG. 2) of thethreaded post 172 (e.g., a hex feature) such that the distal tip 326 isreceivable therein and configured to engage the threaded post 172.

The proximal shaft assembly 330 includes a proximal outer shaft 332, aproximal inner shaft 334, and an adjustment knob 336. The proximal outershaft 332 is configured to be slidably disposed within the connector 329and the proximal base portion 322 of the distal inner shaft 320, whichare each disposed within the outer shaft 310, as described above. Theadjustment knob 336 is slidably disposed over the proximal outer shaft332 and the proximal inner shaft 334 is disposed within the proximalouter shaft 332. Threaded plungers 338 are positioned in lateral sideopenings 336 a of the adjustment knob 336 and are configured to engagerecesses 337 defined in the proximal outer shaft 332 upon actuation ofthe adjustment knob 336 between a height position “H” (FIGS. 24A and24B), a posterior or proximal position “P” (FIGS. 25A and 25B), and ananterior or distal position “A” (FIGS. 26A and 26B). A pin 340 extendsthrough opposed openings 336 b of the adjustment knob 336, alongitudinal opening 332 a defined in the proximal outer shaft 332, andan opening 334 a defined through the proximal inner shaft 334.Accordingly, the adjustment knob 336 may be slid between the heightposition “H” (FIGS. 24A and 24B), the proximal position “P” (FIGS. 25Aand 25B), and the distal position “A” (FIGS. 26A and 26B) relative tothe proximal outer shaft 332 which, in turn, causes a correspondinglongitudinal movement of the proximal inner shaft 334.

The proximal inner shaft 334 further includes proximal and distalrecessed grooves 334 b, 334 c defined therearound, and the connector 329includes pockets 329 a defined therethrough. The proximal and distalrecessed grooves 334 b, 334 c as well as the pockets 329 are configuredto engage/disengage proximal and/or distal ball bearing assemblies 342a, 342 b (see e.g., FIG. 24B) disposed within the proximal outer shaft332 during actuation of the adjustment knob 336 between the height,proximal, and distal positions to effect the function of the drivinginstrument 300. Specifically, the proximal and distal ball bearingassemblies 324 a, 342 b are configured to float above or below theproximal outer shaft 332 to actively engage or disengage the distalinner shaft 320 and/or the outer shaft 310.

As shown in FIGS. 24A and 24B, when the adjustment knob 336 is in theheight position “H”, the proximal and distal ball bearing assemblies 342a, 342 b are disengaged from the proximal and distal recessed grooves334 b, 334 c (FIG. 23) of the proximal inner shaft 334, as well as thepockets 329 a (FIG. 23) of the connector 329. Accordingly, actuation ofthe proximal outer shaft 332 of the proximal adjustment assembly 330allows both the outer shaft 310 and the distal inner shaft 320 to beactuated such that the proximal and distal adjustment assemblies 150,170 of the spinal implant 100 are simultaneously adjusted.

When the adjustment knob 336 is moved to the posterior position “P”, asshown in FIGS. 25A and 25B, the proximal inner shaft 334 is slidproximally such that the proximal ball bearing assembly 342 a isdisengaged from the proximal inner shaft 334 and the distal ball bearingassembly 342 b is engaged with the pocket 329 a of the connector 329.Accordingly, actuation of the proximal outer shaft 332 of the proximaladjustment assembly 330 causes only the outer shaft 310 to be actuatedsuch that only the proximal region 110 a of the spinal implant 100 isactuated.

When the adjustment knob 336 is moved to the anterior position “A”, asshown in FIGS. 26A and 26B, the proximal inner shaft 334 is sliddistally such that the proximal ball bear assembly 342 a is engaged withthe proximal recessed groove 334 c of the proximal inner shaft 334 andthe distal ball bearing assembly 342 b is disengaged from the pockets329 a of the connector 329. Accordingly, actuation of the proximal outershaft 332 of the proximal adjustment assembly 330 causes only the distalinner shaft 320 to be actuated such that only the distal region 110 b ofthe spinal implant 100 is actuated.

It is envisioned that a feedback mechanism (e.g., audible, tactile,etc.) may be incorporated into the insertion instrument 200 and/or thedriving instrument 300 to provide an indication to the clinician ofexpansion and/or retraction of the proximal and/or distal adjustmentassemblies 150, 170 of the spinal implant 100. For example, theinsertion instrument 200 and/or the driving instrument 300 may include aratchet such that each turn, or portion of a turn, produces an audiblesound (e.g., a click) to alert the clinician that the spinal implant 100is being expanded and/or retracted. Further, each audible click mayrepresent expansion or contraction of a predetermined amount (e.g., 2mm). Additionally or alternatively, the insertion instrument 200 and/orthe driving instrument 300 may include a quick release feature (e.g.,that releases a ratchet) so that the surgical implant 100 can be quicklyreduced.

Referring now to FIG. 27, a system 1 for inserting, positioning, and/oradjusting (e.g., expanding) the spinal implant 100 in a disc spacebetween adjacent vertebral bodies with the insertion instrument 200 andthe driving instrument 300 is shown. A clinician removes all or aportion of a disc from between two vertebral bodies (e.g., complete orpartial diskectomy), and scrapes and cleans the endplates of thevertebral bodies to prepare the surfaces for placement of the spinalimplant 100 such that a fusion will occur. Next, the clinician placesthe spinal implant 100 into the disc space using the insertioninstrument 200 by aligning and releasably securing the connectorassembly 230 of the insertion instrument 200 to the spinal implant 100,as described above. The insertion instrument 200 may be pre-attached tothe spinal implant 100 prior to inserting the spinal implant 100 intothe disc space, or may be attached after the spinal implant 100 ispositioned in the disc space. A slap hammer (not shown) may be used withor integrated into the insertion instrument 200 to facilitate placementof the spinal implant 100 into the disc space.

The driving instrument 300, which is positioned in the home position“H”, is then inserted through the lumen 201 of the insertion instrument200. As shown in FIGS. 28A-28C, the driving instrument 300 extendsthrough the insertion instrument 200 such that the open tip 316 of theouter shaft 310 engages the flange nut 154 of the spinal implant 100 andthe distal tip 326 of the distal inner shaft 320 engages the recessedproximal end 172 b of the threaded post 172. The clinician may thenmoves the adjustment knob 336 of the driving instrument 300 to theanterior position “A”, as described above, to actively engage the distalinner shaft 320 (and disengage the outer shaft 310) such that rotationof the proximal outer shaft 332 in a first or second direction rotatesthe threaded post 172 which, in turn, actuates the distal adjustmentassembly 170 of the spinal implant 100, as described above, to adjustthe position (i.e., height) of the distal region 100 b of the spinalimplant 100.

Additionally or alternatively, the clinician can move the adjustmentknob 336 of the driving instrument 300 to the posterior position “P”, asshown in FIGS. 29A-29C and described above, to actively engage the outershaft 310 (and disengage the distal inner shaft 320) such that rotationof the proximal outer shaft 332 in a first or section direction rotatesthe flange nut 154 of the spinal implant 100 which, in turn, actuatesthe proximal adjustment assembly 150 of the spinal implant 100, asdescribed above, to adjust the position (i.e., height) of the proximalregion 100 a of the spinal implant 100.

Various allograft and/or autograft materials may be placed into and/ornext to the spinal implant 100 to assist in the fusion process. By wayof example, it is contemplated that a catheter or similar tubularinstrument may be inserted through the lumen 201 of the insertioninstrument 200 after the driving instrument 300 is removed. Bone orother natural or synthetic graft material may then be injected throughthe catheter or tubular instrument to exit at the far end of theinstrument to provide graft material in and around the spinal implant100. Should the clinician need to adjust the proximal and/or distalheights of the spinal implant 100 once it is expanded, the drivinginstrument 300 would be re-engaged with the flange nut 154 and/or thethreaded post 172, the adjustment knob 336 would be moved to theposterior or anterior position, and the proximal outer shaft 332 wouldbe rotated to drive the flange nut 154 or the threaded post 172proximally or distally.

While embodiments shown and described herein illustrate exemplaryheights of the spinal implant in collapsed, partially expanded, andfully expanded positions, it should be understood that other unexpandedand expanded heights are also contemplated. Thus, it is contemplatedthat a variety of inserting and expanding techniques are achievable withthe spinal implant, the insertion instrument, and driving instrumentdisclosed herein.

For example, the spinal implant attached to the insertion instrument maybe inserted into a disc space between vertebrae with the end plates ofthe exterior surfaces of the upper and lower bodies of the spinalimplant substantially parallel. The driving instrument may then be usedto actuate the proximal and distal adjustment assemblies such that thespinal implant is expanded while maintaining the upper and lower bodiessubstantially parallel to one another until the vertebral bodies areengaged. Thereafter, the proximal and distal adjustment assemblies maybe individually actuated to adjust the disposition of the upper andlower bodies to accommodate lordosis. Alternatively, after the spinalimplant is inserted into a disc space with the upper and lower bodiessubstantially parallel, one of the proximal or distal regions of thespinal implant may be expanded by actuating the corresponding proximalor distal adjustment assembly, followed by either (i) expanding theproximal and distal regions of the spinal implant simultaneously toprovide further parallel expansion, or (ii) expanding the other of theproximal or distal adjustment assembly to adjust the other region of thespinal implant into contact with the vertebral bodies. Thereafter, thespinal implant may be (i) locked in place with the set screw asdescribed below, (ii) further expanded or retracted in parallel byactuating the proximal and distal adjustment assemblies at the sametime, or (iii) further adjusted to conform to the anatomy by alternatelyactuating one or both of the proximal and distal adjustment assemblies.

It is further contemplated that the spinal implant may be adjusted toapproximate the lordosis of the patient by adjusting one or both of theproximal and distal adjustment assemblies prior to inserting the spinalimplant into the disc space, thereby approximating the pre-existinglordotic condition of the patient. After the spinal implant is soadjusted and inserted, the driving instrument may then be used toactuate the proximal and distal adjustment assemblies such that thespinal implant is expanded until the vertebral bodies are engaged.Thereafter, the proximal or distal adjustment assembly may be actuatedto adjust the disposition of the upper and lower bodies of the spinalimplant to accommodate lordosis. Alternatively, after the spinal implantis inserted with the upper and lower bodies predisposed for lordosis,one of the proximal or distal regions of the spinal implant may beexpanded by actuating the corresponding proximal or distal adjustmentassembly, followed by either (i) expanding the proximal and distalregions of the spinal implant simultaneously, or (ii) expanding theother of the proximal or distal adjustment assembly to adjust the otherregion of the spinal implant into contact with the vertebral bodies.Thereafter, the spinal implant may be (i) locked in place with the setscrew as described below, (ii) further expanded or retracted in parallelby actuating the proximal and distal adjustment assemblies at the sametime, or (iii) further adjusted to conform to the anatomy by alternatelyactuating one or both of the proximal and distal adjustment assemblies.

After the spinal implant 100 is manipulated into a desired position, aset screw driver 300 a may be utilized to lock the set screw 10 into thespinal implant 100 to prevent backout of the threaded post 172 andflange nut 154. As shown in FIG. 30, a system 2 includes the spinalimplant 100, the insertion instrument 200, and a set screw driver 300 a.The set screw driver 300 a includes an elongated body 302 having aproximal end 304 configured to engage a rotation instrument (not shown,but which may constitute a T-handle) and a distal end 306 configured toengage the set screw 10 (see e.g., FIG. 1). The set screw driver 300 a,having the set screw 10 releasable attached thereto, is introducedthrough the lumen 201 of the insertion instrument 200 such that the setscrew 10 may be screwed into the threaded inner surface 153 of thelinkage body 152 to lock the spinal implant 100 in the desired position.

With reference now to FIGS. 31-33, prior to the insertion of the spinalimplant 100 into a disc space, a disc spreader 300 b having a bladeportion 308 at a distal end thereof may be utilized to distract the discspace. The blade portion 308 may be sized to act as a trial implantprior to deploying a spinal implant 100 into the disc space. Inembodiments, the blade portion 308 is releasably secured to the distalend of the disc spreader 300 b such that a variety of trial implants maybe attached thereto. The size of the trial implants may range, forexample, in 1 to 2 mm increments and may include both lordotic andparallel versions.

A spinal fixation system may be provided in a kit. The kit is anassembled package including at least one spinal implant 100, aninsertion instrument 200, a driving instrument 300, a set screw driver300 a, and a disc spreader 300 b including a plurality of blade portions308. In embodiments, the kit may include a plurality of spinal implant100 having, for example, different expansion sizes.

Persons skilled in the art will understand that the structures andmethods specifically described herein and shown in the accompanyingfigures are non-limiting exemplary embodiments, and that thedescription, disclosure, and figures should be construed merely asexemplary of particular embodiments. By way of example, it iscontemplated that the insertion instrument and/or driving instrument maybe provided with indicia or other markings or references to indicate therelative position of the threaded post and/or flange nut, so that theposition of the upper and lower bodies relative to one another can beunderstood from the positon of the instrument handles. It is furthercontemplated that the threaded inner surface of the linkage bodyprovided for the set screw may be used to engage an instrument to holdthe spinal implant, either during insertion or removal. It is to beunderstood, therefore, that the present disclosure is not limited to theprecise embodiments described, and that various other changes andmodifications may be effected by one skilled in the art withoutdeparting from the scope or spirit of the disclosure. Additionally, theelements and features shown and described in connection with certainembodiments may be combined with the elements and features of certainother embodiments without departing from the scope of the presentdisclosure, and that such modifications and variation are also includedwithin the scope of the present disclosure. Accordingly, the subjectmatter of the present disclosure is not limited by what has beenparticularly shown and described.

The invention claimed is:
 1. An intervertebral implant, comprising: anupper body for engaging an upper vertebral body; a lower body forengaging a lower vertebral body; a first rotational actuator; a secondrotational actuator; a first adjustment assembly disposed between theupper and lower bodies and adjustably coupled to the upper and lowerbodies so as to change a height between the upper and lower bodies in atleast a first region of the intervertebral implant; a second adjustmentassembly disposed between the upper and lower bodies and adjustablycoupled to the upper and lower bodies so as to change the height betweenthe upper and lower bodies in at least a second region of theintervertebral implant; and a set screw removably positionable in asecured position within the intervertebral implant for locking at leastone of the first and second adjustment assemblies; wherein the firstadjustment assembly is actuatable by the first rotational actuator andthe second adjustment assembly is actuatable by the second rotationalactuator, the first and second rotational actuators being coaxiallyarranged with respect to one another about an actuation axis.
 2. Theintervertebral implant of claim 1, wherein the set screw is configuredto engage at least one of the first and second rotational actuators inthe secured position.
 3. The intervertebral implant of claim 2, whereinthe set screw covers an access opening for the at least one of the firstand second rotational actuators in the secured position.
 4. Theintervertebral implant of claim 1, wherein the first and second regionsof the intervertebral implant include a proximal region and a distalregion, respectively, and wherein the first and second adjustmentassemblies include a proximal adjustment assembly positioned in theproximal region and a distal adjustment assembly positioned in thedistal region, respectively.
 5. The intervertebral implant of claim 1,wherein the set screw is positionable into the secured position byadvancing along threads of the implant arranged coaxially with theactuation axis.
 6. The intervertebral implant of claim 1, wherein theset screw has an opening through a proximal end thereof.
 7. Anintervertebral implant, comprising: an upper body for engaging an uppervertebral body; a lower body for engaging a lower vertebral body; afirst rotational actuator; a second rotational actuator; a firstadjustment assembly disposed between the upper and lower bodies andadjustably coupled to the upper and lower bodies so as to change aheight between the upper and lower bodies in at least a first region ofthe intervertebral implant; a second adjustment assembly disposedbetween the upper and lower bodies and adjustably coupled to the upperand lower bodies so as to change the height between the upper and lowerbodies in at least a second region of the intervertebral implant; and alocking element removably positionable in a secured position within anaccess opening of the intervertebral implant; wherein the firstadjustment assembly is actuatable by the first rotational actuator andthe second adjustment assembly is actuatable by the second rotationalactuator, the first and second rotational actuators being arrangedwithin the access opening, and the locking element covering the accessopening in the secured position.
 8. The intervertebral implant of claim7, wherein the first and second regions of the intervertebral implantinclude a proximal region and a distal region, respectively, and whereinthe first and second adjustment assemblies include a proximal adjustmentassembly positioned in the proximal region and a distal adjustmentassembly positioned in the distal region, respectively.
 9. Theintervertebral implant of claim 8, wherein the first and secondrotational actuators are coaxially arranged with respect to one anotherabout an actuation axis.
 10. The intervertebral implant of claim 9,wherein the locking element is positionable into the secured position byadvancing along threads of the implant arranged coaxially with theactuation axis.
 11. The intervertebral implant of claim 7, wherein thelocking element has an opening through a proximal end thereof.
 12. Anintervertebral implant, comprising: an upper body for engaging an uppervertebral body; a lower body for engaging a lower vertebral body; afirst rotational actuator; a second rotational actuator; a firstadjustment assembly disposed between the upper and lower bodies andadjustably coupled to the upper and lower bodies so as to change aheight between the upper and lower bodies in at least a first region ofthe intervertebral implant; a second adjustment assembly disposedbetween the upper and lower bodies and adjustably coupled to the upperand lower bodies so as to change a height between the upper and lowerbodies in at least a second region of the intervertebral implant; and alocking element removably positionable in a secured position within theintervertebral implant; wherein the first adjustment assembly isactuatable by the first rotational actuator and the second adjustmentassembly is actuatable by the second rotational actuator, the first andsecond rotational actuators being coaxially arranged with respect to oneanother about an actuation axis; and wherein, in the secured position,the locking element engages at least one of the first and secondrotational actuators, thereby locking a respective at least one of thefirst and second adjustment assemblies.
 13. The intervertebral implantof claim 12, wherein the first and second regions of the intervertebralimplant include a proximal region and a distal region, respectively, andwherein the first and second adjustment assemblies include a proximaladjustment assembly positioned in the proximal region and a distaladjustment assembly positioned in the distal region, respectively. 14.The intervertebral implant of claim 12, wherein the locking element ispositionable into the secured position by advancing along threads of theimplant arranged coaxially with the actuation axis.
 15. Theintervertebral implant of claim 12, wherein the locking element has anopening through a proximal end thereof.